Process of forging crank-shafts and similar articles.



A. L. WAHNtH.

PROCESS OF FORGING CRANK SHAFTS AND SIMILAR ARTICLES.

APPLICATION FILED AUG-28. 1914.

1,181,703. Patented May 2, 1910.

2 SHEETS-SHEET 1.

INVENTUR a yfkur L. Warmer BY RO QVS, KVnmtlj WITNFS'SES A. L. WARNER.

PROCESS OF FORGING CRANK SHAFTS AND SIMILAR ARTICLES.

APPLICATION FILED AlJG-ZB. I914.

1 1 8 1 703 Patented May 2, 1916.

2 SHEETS-SHEET 2- ATTORNEYS.

UNITED STAT-13S PATENT OFFICE.

ARTHUR L. WARNER, OF MOLINE, ILLINOIS, ASSIGNOR TO WILLIAMS, WHITE 8:COMPANY, A CORPORATION OF ILLINOIS.

PROCESS OF FORGING CRANK-SHAFTS AND SIMILAR ARTICLES.

Specification of Letters Patent.

Patented May 2, 1916.

Original application filed June 24, 1911, Serial No. 635,112. How PatentNo. 1,108,954, dated September 1, 1914. Divided and this applicationfiled August 28, 1914. Serial No. 859,063.

7 '0 all whom it may concern:

Be it known that I, An'rrinn L. WARNER, a citizen of the United States,residing at Moline, in the county of Rock Island and State of Illinois,have invented certain. new and useful Improvements in Processes ofForging Crank-Shafts and Similar Articles, of which the following is aspecification, reference being had therein to the accompanying drawing.

This invention relates to method of forging crank-shafts or analogousarticles which comprise in addition to the main portion of the shaft acrank wrist or pin portion offset from the shaft line and at least one,or preferably, two webs or arms extending integrally between the wristand main portion of the shaft.

The general o'bject hereof is to enable the manufacture of crank-shaftsin an economical and efiicient manner so as to afford crank-shafts ofhigh degree of strength, uniformity and other desirable qualities.

Particularly it is an object hereof to enable the manufacture ofcrank-shafts in quantities in such way as to afford full stock at thecorners of the bends of the crankshaft, this being one of the problemswith which forge shops have had to contend.

It is a further object hereof to enable the above recited objects to becarried out in the manufacture of a crank-shaft in substantially asingle operation so as to thereby greatly increase the output.

Other objects and advantages will appear in the hereinafter followingdescription or will be apparent to those skilled in the art.

In a general way it may be stated that the method constituting thepresent 'inven tion consists in first bending portions of a bar of metalin such manner as to form the crank arms and wrist with an excessivecrank throw and thereupon displacing the wrist relatively toward theshaft line to secure the desired crank throw, thus causing the metal toflow into the corners of the bends.

The present method will be described more in detail hereinafter inconnection with the description of a convenient form of apparatus forcarrying out such method.

No claim is herein made for the illustrated apparatus, since the samehas been made the subject of a separate prior applicat on of which thepresent application is a dlVlSlOIl. Said prior application has now beenpatented, No. 1,108,954, of September 1, 1914.

A detailed description of the present process W111 be postponed until aconvenient apparatusfor carrying it out has been re ferred to.

In the accompanying drawings forming a part hereof, Figure 1 is aperspective view, taken generally from the right side of the apparatus,its front end being at the left hand of the figure. certain parts beingomitted for clearness of illustration. The finished crank is ready to beremoved, preparatory to the insertion of the heated straight bar orblank which is to be formed into the succeeding crank shaft. i 'ig. 2 isa righthand elevation, indicating a convenient mechanism forreciprocating the crosshead of the bulldozer. Fig. 3 is a centrallengthwise section. Figs. 4, 5 and 6 are top views, more or lessdiagrammatic, indicating different stages in the operation. The topplate C of the anvil block the guides for the dies and other parts areomitted. Fig. 4 shows the initial position. The heated straight bar Y isin place and the interior anvil D is locked in inward position. Fig. 5shows the diagonal dies having moved in ward, thus producing the fourbends in the shaft, or two bends. if the crank has but one web. Fig. 6shows the wrist die and the end blocks forced inward, and the interioranvil withdrawn to its outward position. In this operation all thecorners are upset. This stage of operation is followed by the reversalof the parts to the position shown in Fig. 1. For shafts with flatinstead of round webs the apparatus will be modified according to Figs.7 and 8. which correspond with Figs. 5 and 6. Fig. 9 represents thecrank shaft forged on the apparatus of Figs. 1 to 6. Fig. 10 representsthe crank shaft forged on the apparatus of Figs. 7 and 8. Fig. 11indicates a shaper with means by which its face may be adjusted orrenewed.

By the present invention a crank shaft is made partially by bending andpartially by upsetting in one continuous operation. This affords theimportant advantage that the natural grain or fiber of the metallengthwise of the shaft is not disturbed or distorted to any substantialextent. Conse- (uently a stronger crank shaft is obtained than with adrop forge.

The terms to be used herein first require some explanation. The shapingmembers or dies of the apparatus will sometimes be called shapers. Theygive shape to the crank shaft. In some cases the shapers are activedies, which advance to press the material. Otherwise they are passiveand give shape by resisting active dies. The passive dies will in thedescription be referred to as anvils. This however, is only forconvenience of explanation. It is understood that any die action is onlyrelative. Mechanically a passive anvil reslsting an active die is thesame as though the anvll advanced toward the die. A crank shaft consistsof the following: The shaft proper or the two ends y Fig. 9, extendalong the line of the shaft. The crank webs y y whether there be one ortwo connect the shaft proper with the wrist 3 Forward, means toward thefront of the apparatus. Inward and outward mean toward and from themetal being forged.

The operation begins by bending the metal to the general shape of thecrank shaft, and the operation continues by causing the metals upsettingfor completely filling out the corners. The bending 1S done by theinward movement of shapers, which after bending become passive and giveshape during the upsetting. The upsetting is done by the wrist diemoving toward a yielding anvil, supplemented by forcing the ends of theshaft inward. The metal is thus made to flow into the corner spaces ofall four of the bends. The apparatus for carrying out of this operationcomrises an interior anvil shaped to extend Between the webs of theforged shaft, together with two or more movable dies con verging towardthe anvil. There are shown three dies, a wrist die and two diagonal diesat the side. The diagonal dies effect the bending, and thein operationis followed by that of the wrist or central die. The latter movesdirectly toward the aforesaid anvil, which is constructed so as toyield. Thus the die and anvil movev together, and cause the metal to beupset in the manner stated.

The specific illustrated apparatus will now be referred to.

The reciprocating crosshead A moves along a stationary frame, which mayconsist of two side frame pieces A, A. At the front end of the machineis the abutment opposed to the crosshead A. The

dies and anvils, comprises a heavy casting or bed B. This shouldbe-bolted down upon the frame of the bulldozer. It may have longitudinalribs at its under side to fit snugly between the bulldozer frame partsA, A. This gives an extremely rigid permanent connection. The apparatuspreferably stands horizontally, and the upper side of the bed B isgenerally fiat with raised portions b, b and 6 serving as guides. Thebent crank shaft Y is shown in Figs. 1 and 5 to 10, and theheatedstraight rod or blank Y from which it is made, is shown in Fig. 4.The finished crank comprises in succession shaft part 3 web 3 wrist orpin web 3 and shaft part 3 At the front of the heated blank are thepassive shapers or anvils C- and D. At the opposite side are the activedies F, G, H. The main anvil C is stationary, although it should be sosecured as to permit adjustment when desired. A cover plate, C, confinescertain parts within the anvil C. This top plate 15 omitted from Figs. 4to 8. The anvil Gis recessed cen-' trally to form a longitudinal way foranvil member D. This divides /the anvil G into two shaping portions,which may be called end shapers. The anvil'member D extends through therecess in anvil block. C, and considerably beyond it, as seen in F lgs.1 and 4. It lies between the two webs and wrist of the finished crank,and gives them. their proper final shape. The main anvil C and interioranvil D together constitute a passive shaper for opposing the movabledies. Relative adjustment is easily permitted for altering thedimensions or throw of the crank shaft. The anvil D ls adapted to besubstantially fixed at certaln times, and shiftable at other times. Astrong spring might be employed to hold it in the inward position ofFigs. 1, 4, 5, and :7, which would subsequently permit yielding.However, a mechanical stop is preferred. For example, the stop E fittedin a transverse way in the anvil C. This stop 1s m its right-handposition in Figs. 1 and 4, being held there by spring 6 In this positionthe anvil member D is secured in its mward location. If the stop E beforced to the left, its recess e admits the anvil D, so that the lattercan recede the proper distance. The anvil D is to be held in its inwardposition as in Figs. 1 and 4, during the formation of the bends in thecrank shaft. The dimensions are calculated to give the crank shaft athrow greater than is finally desired. The operation is, that after thebending is complete, the anvil D is permitted to recede, while thecentral die forces the crank wrist to its proper final position. In thisway sufiicient metal is afforded for filling out the corner spaces atthe bends.

While the stop E may be operated by hand, it may also be operatedautomatically as follows: It has at Its right end, an a justable campiece e which is ada ted to be contracted by cam K, afterwar to bedescribed, for forcing the stop leftwlse at the proper moment.

We come now to the movable dies. The two diagonal dies G, H, may be setpractically at forty five degrees. This direction gives good access forthe purpose of bending. These diagonal benders, together with thecentral wrist die- F, all converge when moved inwardly toward the anvll.The three converging dies all take their motion from the reciprocatingcross-head A of the bulldozer. The central die F may be merely attachedto the crosshead A by a foot f. The die F is of such length as to comeinto operation only after the diagonal dies have completed the bending.For actuating the dia onal dies, there may be cam members J, K, whichare both attached by their feet 7', k, to the crosshead A. The inclinedfront ends of the cam members J, K, act u on rollers g, it, carried onthe diagonal sli ing dies G, H. When the crosshead moves forward, thecams J, K, cause the dies G, H to move diagonally inward upon the blankor straight bar Y, Fig. 4, so as to produce the bends in it as in Fig.5. The cams J, K, are so shaped that when their inclined ends have donethe work of movin the dies, their side-surfaces-hold the dies H, lockedinwardly, as seen in Fig. 5, so that the dies become substantiallystationary, and able to serve as passive shapers during the upsetting.The central die'F has no bending to perform. It is so formed as to givethe proper shape to the crank wrist. The die F may be constructed to bereadily adjustable in length for crank shafts of varying dimensions.

All of the dies F, G, H, may have removable and adjustable faces as inFig. 11, so as to permit replacement when worn, or variation ofdimensions. Guideways are necessary for the diagonal dies G, H. The faceof eachof these dies consists of two slanting surfaces, one adapted topress the metal toward the interior shaper D, and the other toward theend shapers or anvil C. Each die is guided by its shank, which engagesan undercut slideway formed between the raised portions or ribs 6 b ofthe bed. At the final or critical movement of the dies G, H, it ispreferred to give them' further guidance by means of a pair oftriangular projections c, which stand out from the top plate C of theanvil block. Each die has a raised projection g, h, which contacts theprojection c as the dies slide inward. The depressed part of each dieslides under the projection a. They are thus most effectively supportedto resist displacement during any part of the forging operation. Theoutward or idle positionof each die G, H, is sufliciently rearward topermit the original straight bar or blank to be inserted in forgingposition. Any means may be employed for moving the dies outwardly, andsprin s g, h are shown. To move the dies G, 1%,

inwardly, the cams J, K, contact the rollers 51, h, as before ex lained.Each roller 9, h, s simply mounte on a vertical pin extending from thelower part of the diagonal die to an overhanging portion above theroller. There exists a side thrust, tending to force the cams J, K,apart while driving the dies. This is met by a pair of rolls L, L, lyingoutside of the cams while across the top of the machine, from one roll Lto the other, is a rod Z, which gives the necessary bracing. The dies F,G, are timed so that G and H first strike and bend the metal tosubstantially the shape shown, after which the dies G and H becomestationary, while the die Fcomes into action at the wrist portion 3 ofthe crank. The die F tends to drive the wrist inwardly toward the shaftline. It is at this point in the operation that the stop E is shifted tothe left, to allow the anvil member D to be pushed outwardly, as the dieF moves inwardly. This substantially displaces the crank wrist towardthe shaft line, to its desired final position, and causes the flowofmetal aforesaid, into the corner spaces. In this way, the corners maynot only be filled out to make them as strong as other parts, but, infact, the cornersmay be rendered thicker and stronger than elsewhere, ifso desired.

The actual shape of the webs of the finished crank shaft, will dependupon the shape of the side faces of the diagonal dies and the anvilmember. These are concave 1n Figs. 1, 3, 4, 5 and 6, resulting in around web crank as in Fig. 9. By makin the anvil and die faces flat asin Figs. and 8, the crank webs may be converted to a flat form, as inFig. 10, which is a desirable type of crank shaft. The changes are madeby removing and replacing the faces of the d1es, and making thenecessary adjustments of motion. Greater pressure is required in makingfiat webs than round webs, and the projections c, a, before referred to,are provided especially for this use.

The upsetting operation is rendered more perfect and complete at allfour of the bends by the following mechanism: An upsetting block M isshown at each side of the machine. These slide laterally and have springm to withdraw them outwardly. The blocks may be slidably connected inany way to the bed. The purpose of these blocks is to press inwardly atthe proper time upon the two ends y y of the shaft. A convenient way toautomatically move the blocks is by employing the same cams J, K, whichhave previousl caused the inward movement of the dies H. The corner ofeach block M is beveled to admit the forward end of each cam, so thatjust before the cams reach the limit of their movement, they operate towedge the blocks M, M, toward each other. The wedgin action of cam J canbe adj usted by means 0 an adjustable attached iece j, which contactsthe upsetting block sooner or later, according to its position. The twoends of the shaft are thus bodily forced inward. In this way the plasticmetal is forcibly acted upon, and caused to flow as required tocompletely fill out the corner spaces. The parts should be so designedthat the blocks M, M, move inwardly at the same time the die F is inoperation, so that the upsetting in all of the corners is simultaneous.

Each of the cams J, K, is seen to perform three operations. First, itmoves its diagonal die inwardly, and thereafter holds it rigidly inplace. Secondly, the cam shifts the stop E to the left to permit theanvil member D to recede, and at about the same time forces theupsetting block M inwardly; while at the same time the die F comes intooperation pushing the anvil member D ahead of it. Thus, from thecrosshead of the machine, all the operations are performed. Manifestly,the mechanical connections between the several parts may be indefinitelyvaried.

The described production of the complete crank shaft will be seen toconstitute a single operation. This includes, not only the formation ofthe wrist and webs and the four bends, but also the filling out of allof the corners.

As compared with the old drop forging process, this invention enables acrank shaft to be manufactured from material of small diameter, becauseafter the operation of the present invention, neither enlargement ofthecorners, nor reduction of the diameter of the shaft is necessary.Thus, both labor and material are saved.

It will be advantageous to re-state the complete operation of thedescribed apparatus.

The crosshead A being in its withdrawn or rearward position, the dies F,G, H,'are retracted so far as to permit the straight blank to beinserted between the dies and the anvil. The middle anvil member Dstands in its inward or rearward position, owing to the springs eforcing the stop E to the right. and thus edging the anvil memberinward. The upset-ting blocks M are held outward by their springs. Fig.4 represents this condition. The forward movement of the bulldozercrosshead will now commence, giving a blow or pressure. First thediagonal dies G, H, strike the heated bar, causing it to be bentinwardly into the general form indicated in Fig. 5 or Fi 7. At thispoint the cams J, K, clear the ies G, H, so as to hold them stationaryas in Figs. 5 and 7. The cam K reaches the stop E and commences to shiftit to unlock the anvil member D as in Figs. 5 and 7. As the crossheadcontinues to move forward, the die F comes into play, also the cams J,K, move the upsetting blocks M inward. As the die F presses on the crankwrist, the anvil member D recede's, and the upsetting blocks M moveinwardly. The receding of the anvil member D is limited. At the extremelimit of the crosshead movement, a final pressure at all parts isbrought to bear, to powerfully squeeze the heated metal and fillit outto the predetermined accurate shape desired. This stage is indicated inFigs. 6 and 8.

The forward movement of the crosshead.

might be abrupt or gradual, and might even consist of a series ofimpulses. The crank shaft being in completed form as in Figs. 6 and 8,the crosshead withdraws completely to the rear. This condition isillustrated in Fig. 1. The finished crank shaft may now be taken out anda new heated blank inserted.

A valuable part of this invention is that extensive upsetting may beobtained. Actual collars may be produced at the point where shaft andweb meet. Adjustments may be easily made in many obvious ways.Alteration of dimensions may be obtained by replacing the dies andmovable anvil. A deeper or shallower recess in the stop E will changethe crank throw and the extent of upsetting. The size or extent ofmovement of the upsetting blocks M determine the amount of upsettingat'the lower bends.

It will be seen that a method has been described attaining the objectsand advantages and operating on the principles of the present invention.Since the detail of the several steps and the relative order ofperformance thereof and other described features may be varied withoutdeparting from the main principles, there is no intention to restrictthe present invention to such features excepting as set forth in theappended claims.

What is claimed is:

1. The method of forging crank shafts consisting in bending the heatedbar of metal into the general shape bf the crank shaft while givingsupport thereto at the interior of the wrist and webs, and immediately,before any substantial cooling of the bar, partially withdrawing suchsupport and simultaneously applying exterior pressure to give the finalshape to the wrist and webs and to upset metal into the corners of thebends.

2. Method of making a crank shaft from a bar, which method consists insupporting the wrist section of the heated bar, bending the bar adjacentto such supported section to produce the webs and so as to give thewrist an excess throw, giving support to the webs at their exteriorsldes, and forcing the wrist in a direction toward the axis andsimultaneously withdrawing its support in the same direction, whereby togive the crank shaft its final desired throw.

3. The method of making crank-shafts which consists in first bendingportions of a bar of metal in such manner as to form the crank webs andwrist with an excessive crank throw, and thereupon displacing the wristrelatively toward the shaft line to secure the desired crank throw thuscausing.

the metal to flow into the corners of the bends.

4. The method of making crank-shafts which consists in first bendingportions of a bar of metal in such manner as to form the crank webs andwrist with an excessive crank throw, and thereupon displacing the wristrelatively toward the shaft line to secure the desired crank throw whileconfining the webs, thus causing the metal to flow into the corners ofthe bends.

5. The method of making crank-shafts which consists in first bendingportions of a bar of metal in such manner as to form the crank webs andwrist with an excessive crank throw, and thereupon displacing the wristrelatively toward the shaft line to secure the desired crank throw whileconfining the webs, thus causing the metal to flow into the corners ofthe bends, and shaping the corners during such flow into the corners.

6. The method of making crank shafts which consists in first bendingportions of a bar of metal in such manner as to form the crank webs andwrist with an excessive crank throw while supporting the interior sideof the wrist, and thereupon withdrawing such support and displacing thewrist relatively toward the shaft line to secure the desired crankthrow, thus causing the metal to flow into the corners of the bends.

7. Method of forging crank shafts and the like from a heated metal barwherein the heated bar is doublybent in a manner for producing the weband wrist (pin) portions with an excessive radius or throw of crank,immediately followed by relative displacement of the crank wrist and theshaft line toward each other in a manner to secure the correct radius orthrow of crank and at the same time cause the excess heated metal toflow into the corner spaces of the bends.

In testimony whereof, I have aifixed my signature in presence of twowitnesses.

ARTHUR L. WARNER.

Witnesses:

HARRY Amswon'rn, JoHN W. LIVINGSTON.

